This invention relates to a pipe proof test fixture generally employed to close the end of a pipe for preliminary testing of a pipe line before or after completion.
Problems arise in closing large diameter thin wall pipe made from synthetic plastics or glass fibers which may be more susceptible to disfigurations than metal pipes and which need greater protection against injury when sealing thereagainst.
It is generally essential to grip the pipe both externally and internally by members clamping the pipe wall radially therebetween, in order that a proper seal may be maintained.
Devices for this purpose have been proposed for metal pipe but are generally not adaptable for use with other pipes due to the mass weight of the device or to its tendency to either deform or disfigure the pipe.
Some devices are so heavy as to require mechanical assist in handling the same, making them cumbersome and slow in application.
Others depend upon deforming of the pipe end in securing the closure against test pressures.
These are particularly unsuitable for closing large diameter thin wall synthetic plastic or glass fiber pipes for proof testing up to two and one-half times the working pressure rating of the pipe.